diff options
Diffstat (limited to 'include/llvm/Target/Target.td')
| -rw-r--r-- | include/llvm/Target/Target.td | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td index 24be2b1..cc76714 100644 --- a/include/llvm/Target/Target.td +++ b/include/llvm/Target/Target.td @@ -28,6 +28,24 @@ class SubRegIndex<list<SubRegIndex> comps = []> { // ComposedOf - A list of two SubRegIndex instances, [A, B]. // This indicates that this SubRegIndex is the result of composing A and B. list<SubRegIndex> ComposedOf = comps; + + // CoveringSubRegIndices - A list of two or more sub-register indexes that + // cover this sub-register. + // + // This field should normally be left blank as TableGen can infer it. + // + // TableGen automatically detects sub-registers that straddle the registers + // in the SubRegs field of a Register definition. For example: + // + // Q0 = dsub_0 -> D0, dsub_1 -> D1 + // Q1 = dsub_0 -> D2, dsub_1 -> D3 + // D1_D2 = dsub_0 -> D1, dsub_1 -> D2 + // QQ0 = qsub_0 -> Q0, qsub_1 -> Q1 + // + // TableGen will infer that D1_D2 is a sub-register of QQ0. It will be given + // the synthetic index dsub_1_dsub_2 unless some SubRegIndex is defined with + // CoveringSubRegIndices = [dsub_1, dsub_2]. + list<SubRegIndex> CoveringSubRegIndices = []; } // RegAltNameIndex - The alternate name set to use for register operands of |